(1) Field of the Invention
The invention relates to a composition of an anti-scale-forming agent for dispersing scales and for anti-oxidation, and more particularly to an additive which can be added during a chemical process of a heat-exchanger, a reactor, a distillation tower or the like in a power plant, a petroleum refinery or the like chemistry plant.
(2) Description of the Prior Art
An anti-scale-forming agent is one of typical chemicals that are widely used in petroleum-related and petroleum-refinery industry. Generally, in an intern process of the industry including an oil-cracking process, a reforming process or a de-ethylene process, the reaction temperature may be as high as 200xcx9c500xc2x0 C. Meanwhile, hydrocarbons in a reaction chamber will be deformed through oxidation or polymerization to generate scales. The scales accumulated in the piping and the furnace wall may affect the processing flow, more even block the valves and piping, and lower the heat-transfer efficiency. As a result, energy is wasted and production will be inevitably reduced due to frequently shutdown for cleaning the scales in the piping. Therefore, usage of anti-scale-forming agent in a chemistry plant is important and frequently seen.
The forming of scales is one of general chemistry phenomena. The scale is a gel-form or carbonic-acid coke product that is cracked from a polymer, in which the polymer is formed from a reaction mechanism of free radicals through oxidation upon impurities or the hydrocarbon itself. In addition, in the case that the impurities include metal substance such as Cu or Fe, the forming of free radicals will be accelerated and thus the forming of scales will be serious. Therefore, the anti-scale-forming agent is usually made to be a good anti-oxidizer or a metal de-activator. Actually, there are already several kinds of the anti-scale-forming agents in the market to meet various applications in the industry; such as the U.S. Pat. No. 4,775,495 disclosing a control method upon oxidation for a petroleum-related process, and the U.S. Pat. No. 5,211,836 introducing anti-oxidants and an interface-dispersing theory for various process to enhance economic efficiency.
Accordingly, it is a primary object of the present invention to provide a composition for an anti-scale-forming agent that can disperse the scales and prevent from the oxidization. The scale-dispersivity of the agent is obtained through a dispersing theory for a hydrophilic/oil-philic balanced interface agent in a molecular formula. By integrating the dispersivity and the anti-oxidization in a single polymer, the excellent anti-scale-forming agent of the present invention can be formed and can be applied to the petroleum-refinery and other chemistry processes for providing effects of anti-oxidizing and anti-scale-forming.
To achieve aforesaid purposes, the composition of the anti-scale-forming agent in accordance with the present invention includes polyalkylenes, amines phosphorous and oxygen in a polymer for providing substantial dispersivity and anti-oxidization. The chemical formula of the polymer can be expressed as:
(R1R2)xPOR23xe2x88x92x
in which R1 and R2 are selected from polyalkylenes, poly etheramines or polyamines having oxyakLenes. In the expression, O is oxygen, P is phosphorous, and x is 1 or 2.
In application, aforesaid formula (R1R2)xPOR23xe2x88x92x can be chemically structured as follows. 
R3=alkyl, e.g. polyisobutyleneyl (PIB)
In addition, the structure shown above can be obtained through the following reaction.
x=1 or 2
(A) is made by the following formula: 
(B)+polyisobutylenesuccinic anhydride (PIBSA) {right arrow over (Different Mole Ratio)}xe2x80x83xe2x80x83(A)
Select one of polyalkylenes formed by alkylenes through a polymerization reaction. The polyalkylene is then used to derive an acid-anhydride, and the acid-anhydride is further used to form an additive product through reaction with oxygen and phosphorous containing amine. The additive product has a high oil-resolvability, and at least two amines for bonding effect, and phosphide for anti-oxidizing. The additive product as the anti-scale-forming agent according to the present invention can integrate at least two characteristics into a single polymer so that it can contribute greatly to the oil-refinery factories and other chemistry factories.
All these objects are achieved by the composition of the anti-scale-forming agent described below.